Probiotics are "good" bacteria that live in your intestine and help your body fight off infections and diseases. They also may help with digesting food. Two of these bacteria are called Lactobacillus acidophilus and Bifidobacterium bifidum. If you don't have enough probiotics in your gut, you may have gas, stomach problems, diarrhea, yeast infections, and other more serious infections in your intestine.

Noticeable symptoms of a vitamin B12 deficiency can take years to show up. Irritability, weakness, numbness, anemia, loss of appetite, headache, personality changes, and confusion are some of the signs and symptoms associated with very low levels of vitamin B12. Low levels of this vitamin may also be associated with an increased risk of colon cancer, heart disease, brain problems, and birth defects.

The major symptom of vitamin K deficiency is that your blood doesn't clot as it should. You might notice that you bruise easily or have nosebleeds or bleeding gums. Women may have heavy periods. Internal bleeding, which can be life-threatening, may also be caused by lack of vitamin K.

The information presented here covers some of the nutrients that may be lowered when you take certain medications. The signs and symptoms listed can be caused by other conditions. So if you have these signs and symptoms, it doesn't always mean you have low levels of these nutrients. Many things affect the level of nutrients, including your medical history, diet, and lifestyle, as well as how long you have been taking the medication. Please talk with your health care provider. He or she can best address your health care needs and see if you are at risk for low levels of any nutrients.